Exercise machines in general are well known in the prior art. These machines fall generally into two basic categories, this is, passive, wherein the energy for actuation of the machine is supplied by an outside source, and active, wherein the energy for operating the machine is supplied by the user. As will be disclosed in more detail below, the present invention falls into the former or passive categorY. Immediately below is a disclosure of several prior art patents known to the applicant and which collectively constitute examples of both the above-mentioned categories.
The closest prior art patent appears to be U.S. Pat. No. 3,605,732 to RAPOZA. Rapoza discloses a passive exercise machine which can exercise the feet and also the ankles and wrists, if special brackets are used with the machine. The machine has a flat, planar support surface which is pivotally supported by two vertical arms through the use of an axle attached to the planar surface and journaled in holes formed in the arms. The machine is driven by a motor connected to a crank arm which is connected to the rear edge of the planar surface by a turnbuckle mounted between two springs. Users of the machine must wear special shoes to which are attached base plates having stud-like members which must be inserted into any one of a number of apertures in the planar surface and be fastened to the planar surface with butterfly wing nuts.
The above-described device has several disadvantages. First, it takes considerable preparation to get ready to use the machine, since one has to put on special shoes having attached base plates and studs, the studs have to be inserted into apertures in the planar surface and wing nuts then have to be attached and tightened down on the underside of the planar surface. This is exceptionally awkward for the user to do and may well require the services of a second person to "hook up" the user to the machine. Secondly, the machine is completely open with the moving parts of the drive system exposed, which creates a potential safety hazard. Thirdly, the planar surface is biased to the normally level position by several springs and the oscillatory motion is imparted from the crank arm to the planar surface through two springs and a turnbuckle. Thus, the device has a "springy" or unstable feel to it, rather than a firm, solid and stable feel. Moreover, the springs, since they expand and contract with each movement of the planar surface, will suffer metal fatigue after a finite number of flexures, thus causing a requirement for frequent maintainance of the device. Fourthly, since the oscillatory motion is imparted to the planar surface through springs rather than through a solid link, the planar surface is caused to flop up and down each time the crank arm pauses over center, rather than to impart a smooth, rhythmic motion to the planar surface. Lastly, since the planar surface is designed to be normally level, it is not positioned at the right angle of elevation for comfortable exercising of the feet and ankles.
Another prior art device, shown in U.S. Pat. No. 3,071,130 to HOYER et al, is a leg exercising device. This device consists of an open frame attached to a couch and supporting a flat member which supports a patient's leg. The flat member is pivoted at the end where it is attached to the couch. Also, the flat member has a motor-driven system for tilting the leg-supporting member through a predetermined arc. This device also has the disadvantage that it is of open construction with its drive mechanism exposed, and thus it also represents a safety hazard. In addition, the arrangement of the device is well-suited for exercising a person's leg, if the person is lying down. However, it is not suitable for exercising a person's foot or ankle, in either the prone or sitting position.
Another prior art patent is U.S. Pat. No. 2,186,105 to HALL. The Hall device is not a machine for exercising the feet or ankles. Hall calls his device a "manipulator". Actually, it is a machine for massaging the bottoms of the feet in the areas of the arches and the front portion of the heels, by use of round or rectangular mechanical fingers, which protrude up through holes in his foot plate. Hall has a sloping top on his base but has no way of freely moving either the top of his device or his platform with respect to his base. His platform is only slightly moveable through the use of a concentric cam height adjustment.
Still another prior art patent is U.S. Pat. No. 3,525,522 to PILLER. This invention is an active, friction-type foot exercising device. The device has two foot pedal treads which are receded into a base and pivotally attached to the base at their centers. This comparatively simple device accomplishes its purpose as a foot or ankle exerciser but has little flexibilitY in what It can do. Also, it requires the active participation of the patient, since it is not a powered exerciser.
U.S. Pat. No. 2,235,158 to KRENZKE shows an invention which looks somewhat similar to the present invention. However, it is a vibrator, not a foot exerciser. Krenzke has a top platform with sides which overhang his base but he contemplated no free movement of his top with respect to his base, since his platform is securely fastened to his base with screws.
TIETSWORTH, in U.S. Pat. No. 4,628,909, shows a passive machine for exercising a patient's arms and legs, while the patient is in a supine position. However, no provision is seen for exercising the feet or ankles of a patient or exercising a patient's legs while in the sitting position.
Thus, it may be seen that none of the above-cited prior art patents known to the applicant provides a modern, passive exercise machine which can be used by a patient in the sitting position and which provides both safe operation and reliable, smooth, and stable operation over a long period of time.
Therefore, the object of this invention is to provide a modern, passive exercise machine which can be used comfortably by a patient in the sitting position to exercise the feet, ankles and leg muscles.
A further object of this invention is to provide an exerciser which can furnish gentle, stable, positive and rhythmic motion to the platform in order to exercise the feet, ankles and large leg muscles while the patient is in the sitting position
Still another object of the invention is to provide a completely enclosed exerciser device which is safe for all patients, including those who are mentally ill, retarded, senile or have Alzheimer's disease.
Yet another object of this invention is to provide an exercise machine having a movable platform suspended above a stationary base in such a manner that the platform is freely capable of both pivotal and oscillatory movement without touching the top edges or vertical sides of the base and yet, the platform cooperates with the base to completely enclose the machine.